OpenSpace Planetarium Lesson

Seasons & Earth's Orbit

A dome-ready investigation where young learners watch the sun, follow Earth's yearly trip, and compare the winter and summer night sky.

A

Purpose

Anchoring phenomenon: On a winter night you can find Orion's Belt in the sky. On a summer night, it's gone, and different stars are out instead. Every winter, Orion comes back.

Driving question: Does the sky look the same all year long?

Teaching goal: Give young students a first, concrete experience of a repeating yearly pattern. They watch the sun rise and set, see Earth travel around the sun, and compare the winter and summer night sky.

Students observe, compare, and describe what changes from season to season. At this level, we notice the pattern and that it repeats every year. We do not explain why it happens.

B

NGSS Alignment

Performance Expectations:

  • 1-ESS1-1 — Use observations of the sun, moon, and stars to describe patterns that can be predicted.
  • 1-ESS1-2 — Make observations at different times of year to relate the amount of daylight to the time of year.
Science & Engineering Practice

Analyzing and Interpreting Data

Students use observations of the sun, Earth's path, and the dome sky to describe patterns in the natural world.

Disciplinary Core Idea

ESS1.A: The Universe and its Stars & ESS1.B: Earth and the Solar System

ESS1.A: Patterns of the motion of the sun, moon, and stars in the sky can be observed, described, and predicted.

ESS1.B: Seasonal patterns of sunrise and sunset can be observed, described, and predicted. Students compare how long the sun stays up in each season.

Crosscutting Concept

Patterns

Students notice what changes from season to season and that the same changes happen again every year.

Evidence of Three-Dimensional Learning

  • Students make predictions before each reveal.
  • Students watch the sun rise and set, and compare how long it stays up in each season.
  • Students observe Earth at four stops along its yearly trip around the sun.
  • Students compare the winter and summer night sky and name what changed.
  • Students describe the pattern as one that repeats every year.
NGSS Dimension How this lesson supports it
Science and Engineering Practice Analyzing and Interpreting Data
Disciplinary Core Ideas ESS1.A: The Universe and its Stars; ESS1.B: Earth and the Solar System
Crosscutting Concepts Patterns
Assessment Evidence Predictions, verbal observations during the dome, worksheet drawings of the winter and summer sky, and student descriptions of what changes and whether it repeats.
C

Preparation

Materials

  • Crayons and a pencil (for the classroom worksheets)
  • Student Worksheet: "Seasons & Earth’s Orbit Worksheet"
  • Extension Worksheet: "My Season Sky Wheel" (2 paper plates and 1 brad fastener per student, scissors)
  • OpenSpace Software (Nightsky/Single-Fisheye)

Worksheets

Open the student handout and optional extension activity before starting the lesson.

Educator Background

Earth travels around the sun once a year on a tilted axis. The tilt causes the seasons and changes how long the sun stays up. Earth's trip around the sun is why we see different stars at night in different seasons. This is background for you. Do not teach the cause to K–2 students.

When you show Earth's path around the sun, keep your words simple: "Here is Earth in winter. Here is Earth in summer." Avoid talking about tilt or distance from the sun.

For Kindergarten, focus on talking and pointing. For Grade 2, ask students to predict what the next season's sky might look like.

OpenSpace Setup (before students arrive)

  • Display mode: Single-Fisheye
  • Locations: Steps 1–3 start at the equator, where sunrise and sunset are easiest to watch. Step 4 runs in Chicago. Steps 5–7 show Earth's orbit from space. Steps 8–13 and the Same Clock extension use the dome's location (39.0° N, 105.5° W). The buttons handle every jump for you.
  • Run each button once before class so you know what students will see and how long each one takes.
  • Constellation images start off. Turn on only the one you are talking about.
E

Procedure

Set up the dome and review the horizon

Today we are going to be astronomers. Astronomers are scientists who study the sky. We will make predictions and watch closely to see how the sky changes during the year.

This places us at the equator at 5:30 in the morning, just before sunrise. Time is paused and the compass letters are on.

Look at the bottom edge of the dome. That is the horizon, where the sky meets the ground. Where does the sun come up in the morning? Where does it go down at night?

Pause for responses.

Watch sunrise

Let's watch the sun come up. Keep your eyes on the horizon.

Time speeds up and stops on its own at midday, in about 40 seconds.

Where did the sun start? Which letter is it near?

Guide discussion toward:

  • the sun comes up near the E
  • the sun climbs higher in the sky

Watch sunset

Now let's watch the rest of the day.

Which letter is the sun close to now?

Guide discussion toward:

  • the sun goes down near the W
  • it sets on the other side from where it came up

The sun comes up on one side of the sky and goes down on the other side. It does this every single day.

One day in each season

Now let's watch one whole day in each season. Watch how long the sun stays up in the sky.

Each button runs one day from sunrise to sunset and stops on its own. Each run takes about 1 to 1½ minutes. The summer day runs the longest.

After each day, ask: Was the sun up for a long time or a short time?

Guide discussion toward:

  • the summer day was the longest
  • the winter day was the shortest

When all four days are done, hide the compass letters.

Zoom out to see Earth's trip

Let's leave the ground and zoom way out into space.

Pause and let students react.

That that circle moving around the star in the center (the Sun) is our home, Earth. Earth is always traveling. It takes one whole year to go all the way around the sun.

Everyone, use one finger to draw a big circle in the air. That is Earth's trip around the sun.

Visit four stops on Earth's trip

Let's stop Earth at four places on its trip.

At each stop, just name the season. Don't explain why.

Does Earth ever stop traveling?

Guide discussion toward:

  • Earth keeps going around and around
  • it takes the same trip every year

Return to the dome

Let's fly back home to the ground.

Predict the winter sky

Think about winter. Is it hot or cold? Does it get dark before dinner or after dinner?

When it gets dark in winter, will we see lots of stars, or no stars at all? Thumbs up for lots, thumbs down for none. Tell a neighbor your prediction.

Reveal the winter sky

Look up! Do you see stars? Was your prediction right?

Let students point and call out what they see before you name anything.

Find Orion's Belt

Everyone hold up three fingers in a row. That is Orion's Belt! Three stars in a straight line. Point your three fingers up at the three stars.

Optional: Most stars look white. Can you find one that looks a little orange, like a campfire? (Betelgeuse, at Orion's shoulder.)

Predict the summer sky

Now it's summer. It's hot outside and school is out. When it gets dark in summer, will we see Orion's Belt again? Thumbs up for yes, thumbs down for no. Tell your neighbor your prediction.

Reveal the summer sky

Can anyone find Orion's Belt? Look all around!

Pause while students search.

Guide discussion toward:

  • Orion is gone
  • different stars are out in summer

Find the Big Dipper

See these bright stars? They make a shape like a big spoon. This is the Big Dipper. It is part of a star picture called the Great Bear.

Cup your hand like a spoon and pretend to scoop water. Now trace the Big Dipper with one finger. Four stars make the bowl, and three stars make the handle.

Optional: Are any of these stars orange like the campfire star we found in winter?

Teacher note: The Big Dipper is in the sky all year from here. In summer it is high in the northwest. In winter it is low in the northeast. If a student spotted it in the winter sky, say: "Great observing! The Big Dipper is always nearby, but Orion is the one that goes away."

Conclusion

In winter, we see Orion's Belt. In summer, Orion is gone, and the Big Dipper is way up high. The stars change with the seasons, and every winter Orion comes back again.

What did we see in winter? (Students hold up three fingers in a line.) What did we see in summer? (Students make the scooping hand.)

Carefully exit the dome one at a time. Be mindful of low-light conditions and walk slowly.

Back in the classroom, hand out the Student Worksheet. Students draw the sun on the horizon, circle long or short day for summer and winter, circle their predictions, and draw Orion's Belt and the Big Dipper. Close with a group share: What is one thing that was different between the winter sky and the summer sky?

Important language: At this level we do not teach why the sky changes. We only notice that it changes, and that it changes the same way every year.

F

Extensions

Same Clock, Different Sky

Show 4:00 PM in winter and 4:00 PM in summer, back to back. Where is the sun each time? Is it high in the sky or low near the ground?

My Season Sky Wheel

Students build a paper-plate wheel that turns to show the sky in each season. It shows that the sky changes, then repeats. See the Extension Worksheet.

Shadow check

On sunny days in different seasons, have students trace their shadow at the same time of day and compare the tracings.

G

Assessment

Student evidence to collect: predictions, verbal observations during the dome, worksheet drawings of the winter and summer sky, and a description of what changed and whether it repeats.

Dimension Beginning Developing Proficient
Science & Engineering Practice
Analyzing & Interpreting Data
Watches the dome but does not describe what they see. Describes what they see when prompted. Describes what they see on their own and compares it to their prediction.
Disciplinary Core Idea
ESS1.A / ESS1.B
Does not notice a difference between seasons. Names one difference between seasons with support (the sky or how long the sun is up). Names a specific difference on their own, such as "Orion was gone in summer" or "the sun was up longer in summer."
Crosscutting Concept
Patterns
Does not connect the changes to a pattern. Says the sky changes, with prompting. Says the changes happen again every year, or predicts what the next season will show.
Worksheet Evidence Drawings missing or not connected to the dome. Completes some parts of the worksheet, such as one night-sky drawing. Completes the sun drawing, the long/short day circles, and both night-sky drawings, and can tell what is different.